package org.arch_learn.global_session.spring_redis_session.interceptor;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.util.Enumeration;

public class MyWebMvcInterceptor implements HandlerInterceptor {
    /**
     * 之前执行（进入Handler处理之前）
     * 可以进行权限验证
     *
     * @param request
     * @param response
     * @param handler
     * @return true放行，false中止程序
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        HttpSession session = request.getSession();
        System.out.println("===============>id:" + session.getId());
        Enumeration<String> attributeNames = session.getAttributeNames();
        while (attributeNames.hasMoreElements()) {
            String nextElement = attributeNames.nextElement();
            System.out.println("=================>" + nextElement + ":" + session.getAttribute(nextElement));
        }

        String requestURI = request.getRequestURI();
        System.out.println("==================>当前uri:" +requestURI);
        Object username = session.getAttribute("username");
        if (null == username) {
            System.out.println("未登录，请登录！");
            response.sendRedirect(request.getContextPath() + "/to-login");
            return false;
        } else {
            System.out.println("已登录，请求放行！");
            return true;
        }
    }

    /**
     * 之中执行（Handler处理完毕但尚未跳转页面）
     *
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    }

    /**
     * 之后执行（Handler处理完毕而且已经跳转页面）
     *
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    }
}
